---
title: "Andromeda Galaxy: facts, distance and size – Krillion Space"
description: "The Andromeda Galaxy is the nearest large galaxy to the Milky Way, a spiral of roughly a trillion stars. Size, distance and sourced facts."
url: https://krilion.app/atlas/andromeda
language: en-US
---

# Andromeda Galaxy

Spiral galaxy. Depth 49 on the Krillion Space voyage, in the Galactic core and beyond.

The Andromeda Galaxy is the nearest large galaxy to the Milky Way, a spiral of roughly a trillion stars. It is bright enough to see without a telescope, and about a century ago it became the object that showed astronomers other galaxies exist beyond the Milky Way.

![The Andromeda Galaxy at depth 49 in Krillion Space, from a GALEX ultraviolet photo (NASA / JPL-Caltech).](https://krilion.app/assets/atlas/andromeda.webp)

## Fact sheet

- **Type:** Spiral galaxy
- **Distance:** About 2.5 million light-years from Earth
- **Size:** About 152,000 light-years across (estimates range up to about 220,000)
- **Constellation:** Andromeda
- **Position in the sky:** Right ascension 0h 43m, declination +41° 16′
- **Seeing it from Earth:** It can be seen with the naked eye from a dark site, and even under moderate light pollution, as a soft oval glow; for northern observers it is best on autumn evenings, with NASA naming November as the best month.
- **On the voyage:** Depth 49, in the Galactic core and beyond section of the route, the last charted landmark, after the Large Magellanic Cloud

## Things to know

- No one knows who first noticed it because it is visible without a telescope, but the earliest surviving record is in the Persian astronomer al-Sufi's Book of Fixed Stars from 964. ([NASA](https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-31/))
- About a century ago Edwin Hubble showed that this 'spiral nebula' lies far outside the Milky Way, proving it is a separate galaxy. ([ESA/Hubble](https://esahubble.org/news/heic2501/))
- Hubble's 2025 panorama of Andromeda, stitched from about 600 separate fields, has at least 2.5 billion pixels and shows more than 200 million stars, out of an estimated trillion in the galaxy. ([ESA/Hubble](https://esahubble.org/news/heic2501/))
- Andromeda is approaching the Milky Way at about 400,000 km/h (250,000 mph), and a 2012 NASA analysis predicted the two galaxies would collide in about 4 billion years. ([NASA](https://science.nasa.gov/missions/hubble/nasas-hubble-shows-milky-way-is-destined-for-head-on-collision/))
- A study published in 2025 that included newer data concluded there is only about a 50% chance that the Milky Way and Andromeda merge within the next 10 billion years. ([arXiv](https://arxiv.org/abs/2408.00064))

## Sources

- [NASA – Messier 31 (The Andromeda Galaxy)](https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-31/)
- [ESA/Hubble – Hubble traces hidden history of the Andromeda Galaxy (heic2501)](https://esahubble.org/news/heic2501/)
- [NASA – Hubble Zooms into the Rosy Tendrils of Andromeda](https://science.nasa.gov/missions/hubble/hubble-zooms-into-the-rosy-tendrils-of-andromeda/)
- [Sawala et al. 2025 – Apocalypse When? No Certainty of a Milky Way–Andromeda Collision (arXiv:2408.00064)](https://arxiv.org/abs/2408.00064)

## On the route

- Previous landmark: [Large Magellanic Cloud](https://krilion.app/atlas/lmc)
- [The whole Star Atlas](https://krilion.app/atlas)
- [Fly the voyage yourself](https://krilion.app/d/): every right answer warps your ship one stop deeper.